Exhaust Catalyst Heating for Low-Temperature Regeneration
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Solution Overview
Problem
Existing exhaust systems face challenges in effectively regenerating particulate filters during extended idling periods, as active regeneration is undesirable due to high temperatures and passive regeneration is inefficient at low exhaust temperatures, leading to potential filter clogging and engine malfunction.
Innovation Solution
An exhaust control system with an oxidation catalyst and a heating device, controlled by a controller that detects particulate filter loading and engine temperature, selectively heats the catalyst to activate regeneration at low temperatures, implementing a 'passive+' regeneration strategy to maintain efficient particulate matter removal without excessive fuel consumption.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If active regeneration is used to remove particulate matter from the filter, then the particulate filter can be effectively regenerated, but the exhaust temperature becomes too high which creates safety hazards when the machine is stationary
Solution Approach 1:
The patent changes the temperature parameter by using a heating device to warm the oxidation catalyst to a specific activation temperature range, enabling passive regeneration at lower temperatures than active regeneration, thus avoiding the harmful high temperature effects while maintaining regeneration effectiveness
2Object-affected harmful factors
If passive regeneration is used during extended idling, then the exhaust temperature remains low and safe, but the oxidation catalyst cannot function properly at low temperatures leading to incomplete regeneration
Solution Approach 1:
The heating device performs preliminary action by warming the oxidation catalyst to its activation temperature range before passive regeneration is needed, enabling the catalyst to function properly at low exhaust temperatures during extended idling conditions
3Reliability
If the heating device is activated to warm the oxidation catalyst during low temperature conditions, then the catalyst activation temperature is achieved enabling passive regeneration, but additional energy is consumed
Solution Approach 1:
The controller monitors exhaust temperature and particulate filter loading conditions, and only activates the heating device when both low temperature conditions and high soot loading are detected, optimizing energy usage by avoiding unnecessary heating while ensuring catalyst activation when needed
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The system ensures effective particulate filter regeneration during cold conditions, reducing the risk of clogging and improving engine performance by selectively heating the catalyst to promote combustion of trapped particulate matter, thereby optimizing fuel efficiency and extending engine operation.
Implementation Method 1
Passive regeneration involves the use of a catalyst to reduce an oxidizing temperature of the trapped particulate matter such that it can be continually burned away
Implementation Method 2
a heating device located to selectively warm the oxidation catalyst to within the activation temperature range
Implementation Method 3
an oxidation catalyst located upstream of the filter. The oxidation catalyst converts NO from an engine's exhaust to NO2, which is then used to oxidize particulate matter trapped within the DPF
Data Source
AI summary
An exhaust control system for use with a combustion engine is disclosed. The exhaust control system may have an exhaust passage configured to receive a flow of exhaust from the combustion engine, a particulate filter located within the exhaust passage, and an oxidation catalyst located upstream of the filter. The oxidation catalyst may be configured to promote regeneration of the particulate filter and may have an activation temperature range. The exhaust control system may also have a heating device located to selectively warm the oxidation catalyst to within the activation temperature range, and a controller in communication with the combustion engine and the heating device. The controller may be configured to detect a loading of the particulate filter exceeding a first loaded threshold amount, and to detect a low temperature condition of the combustion engine. The controller may further be configured to activate the heating device to warm the oxidation catalyst when the loading of the particulate filter exceeds the first loaded threshold amount during the low temperature condition and until the loading of the particulate filter is reduced below a second loaded threshold amount.